


Sans's Pain

by TiredTM



Category: Undertale (Video Game)
Genre: Brotherly Love, Chronic Pain, Gen, Hurt/Comfort, Medical Experimentation, Mild Language
Language: English
Status: In-Progress
Published: 2018-08-02
Updated: 2019-06-18
Packaged: 2019-06-20 22:15:36
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 3,691
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15543300
Author URL: https://archiveofourown.org/users/TiredTM/pseuds/TiredTM
Summary: Sans has chronic pain due to Gaster's experiments. Papyrus finds out that Sans has been hiding this.





	1. Chapter 1

**Author's Note:**

> First work here! Mentions of chronic pain, experimentation, and abuse.  
> Crossposted work, also on FF.net under Tired TM and Tumblr under tiredtmsfics.

_Sans POV_  
“ugh.”  
I groaned as I woke up. Everything fucking hurt. Worse than usual, this morning. Today is gonna be shitty. But I have to pretend I’m OK.  
For Papyrus.  
Alright. Gotta get up. Can’t have Papyrus see how hard it is.  
Easy does it.  
CRACK  
“oh stars, ow.” I whimper, tears starting to form in my eye sockets.  
One pop down, a dozen to go. My joints pop, crackle, and snap as I roll my shoulders and twist my back. I take the time to pop the joints of each finger, my knees, ankles, and toes. Sighing in relief, I lay back down. I can’t let Paps know I’m awake before he is. He’ll know something’s wrong if I do that. I’ll just relax here till he comes to get me up, then I’ll do my thing.  
Yeah, I can do this.  
I can do this.  
Yeah.  
\---  
“SANS! GET UP YOU LAZYBONES! IT’S TIME FOR BREAKFAST!”  
“sure bro. be down in a sec."  
“SANS! GET DOWN HERE! YOU’LL BE LATE FOR WORK!”  
“sure bro.” I pretend to fall asleep again, a simple ploy to keep Paps in the dark.  
Stars, I hate lying to him, but he can’t know.  
He can’t know… about HIM.  
“SANS! YOU BETTER NOT BE ASLEEP AGAIN!! YOU NEED TO EAT BREAKFAST.” I could hear Paps stomping up the stairs as he yelled, coming to get me up. Heh. Classic Paps.  
SLAM  
“SANS, GET UP! YOU NEED TO EAT! WE CAN’T BE LATE TO WORK, WHAT IF A HUMAN  
COMES?”  
My door slams open, bouncing off the wall. Paps comes barging in, ready to get me out of bed. I  
shift, getting ready to get out of bed when...  
“I’VE HAD ENOUGH, SANS. IF YOU WON’T GET OUT OF BED, I’LL GET YOU OUT OF BED  
MYSELF.”  
Papyrus roughly lifted me out of bed by my armpits, causing my pain to flare. I could feel tears beading at the edges of my eye sockets, and the pain lanced it’s way up and down my spine, spreading to the rest of my bones and encompassing my being.  
It hurts, too much, too much I can’t…...  
“AUGH, papyrus, put me down!” I scream, tears streaming down my face.

Papyrus fumbles, causing pain to once again flood through my body, before gently setting me down on my bed and sitting beside me.  
“SANS, WHAT IS WRONG? DID I HURT YOU? TELL ME WHAT HAPPENED.”  
I couldn’t speak yet, tears still streaming down my face from the pain that was just barely starting to fade. I sat there, sobbing, while Papyrus sat by my side. I could feel that he desperately wanted to comfort me, but he was afraid to touch me again. My sobbing slowly got quieter and eventually stopped. Papyrus remained right next to me, waiting for me to explain what was going on. When I had calmed down enough, he repeated his question.  
“SANS, WHAT IS WRONG? DID I HURT YOU? PLEASE SANS, I’M WORRIED ABOUT YOU.”  
“n-no, bro, you didn’t hurt me. i was already hurting when I woke up….”  
“SANS. TELL ME WHY. NOW.”  
“o-ok. i will. it all started with a skeleton known as w.d. gaster. you don’t remember him. nobody does, except me… but he was the royal scientist before alphys. he created the core. when king asgore ordered him to find another way to break the barrier, he started to experiment with creating artificial souls. He failed to make any artificial human souls, but he managed to make several artificial monster souls. most of these souls didn’t survive. but two did. eventually, those souls became you and me. i was brought to life first, but something went wrong, and all of my stats were set to one. i… was experimented on. a lot. He had no intention of keeping me alive or healthy till he noticed that your soul was starting to weaken, so he rushed to anchor you to a body as well. he…. made the mistake of allowing me to help care for you. you became attached. we cared for each other, deep in the lab. it made sure we both survived. then one day, the power went out. The door to our cell opened, and you no longer remembered gaster. but i did. later, i found out he had fallen into the core, and been erased from existence. some traces remained, though. the scars on your hands, my low stats, and the pain. gaster’s experiments caused me to feel pain constantly. some days it’s worse, some days it’s better. but  
it never goes away.”  
“OH, SANS. WHY DIDN’T YOU TELL ME? I COULD HAVE HELPED.”  
“i didn’t wanna worry ya bro. and not remembering gaster was…easier on you. I’ve had never seen you happier. i couldn’t ruin that.”  
“SANS. I SHOULD HAVE KNOWN! YOU WERE IN PAIN, AND I KEPT PUSHING YOU! I’M SORRY SANS.”  
Papyrus gently scooped me into a hug, doing his best not to jostle my sore bones.  
“I’LL GO EASY ON YOU FROM NOW ON. BUT SANS, I NEED TO KNOW YOUR LIMITS. I WON’T BABY YOU, BUT I WANT TO KNOW WHEN YOU’RE HURTING AND YOUR PAIN LEVEL. WE’RE GOING TO NEED TO COMMUNICATE. PROMISE ME YOU’LL KEEP ME INFORMED, SANS.”  
“sure, bro.”  
“PROMISE ME, SANS.”  
“...i promise, Paps.”  
“GOODY. I’M GOING TO STAY HOME TODAY. WE CAN SIT ON THE COUCH AND WATCH THOSE SCIENCE PROGRAMS YOU LIKE TO WATCH SO MUCH.”  
“you’re so cool, bro.” I say, tears trickling down from my sockets.  
“NYEHEHE, OF COURSE!”

Paps carried me down the stairs and got me some ketchup. I later fell asleep leaning against my brother, watching a rerun of a program about the stars. I’ve never felt so comfortable before.


	2. Undyne Finds Out

**Summary for the Chapter:**

> Sans has a bad few days, and Undyne finds out.

Things became a bit easier after papyrus found out about my chronic pain.  
He stopped pushing me quite as hard, although he still bugged me about my socks.  
Occasionally, he’d call in for me to Undyne, let her know that I couldn’t come in. it didn’t happen often, but I appreciated him doing that.  
Today, however… today was day #3 of a really bad bought of pain, the kind that won’t let me get out of bed and has tears sliding down my face. Papyrus has been very worried, and he’s tried everything to ease my pain, from food, to healing magic, to sea tea. None of it’s worked, but his stubbornness is so cool.  
I can hear Papyrus calling in for me again. Undyne doesn’t sound happy about it.  
Not like I can hear what she’s saying. I’m just imagining angry fish noises. Heh. ow.  
I hope Undyne isn’t too mad. I don’t want Paps to have to deal with that.  
___  
“WHAT DO YOU MEAN, HE’S STILL SICK?!?!”  
“I MEAN, HE’S STILL SICK, UNDYNE. I THOUGHT I WAS BEING CLEAR…”  
“NGAA! NOT WHAT I MEANT! You’re both SKELETONS, how do you even get sick?!”  
“THE SAME WAY ALL MONSTERS DO, UNDYNE.”  
“Still, I’m not sure he isn’t just finding another way to slack off. I’m coming over to check.”  
“WAIT, UNDY-”  
-Click-  
“DANG IT. I WAS HOPING TO LET SANS REST. I HAVE TO LET HIM KNOW THAT UNDYNE IS COMING OVER.”  
__  
“SANS?”  
"Y-yea, bro?”  
“UNDYNE DOESN’T BELIEVE THAT YOU’RE SICK. SHE’S COMING TO CHECK HERSELF.”  
“She is? D-damn.”  
“I’M SORRY, BROTHER.”  
“S’not your fault, Paps. I shoulda guessed she’d catch on.”  
I could hear Sans struggling to get the words out. I wish that Undyne had just believed me. It’d be so much easier on Sans if she had.  
I’m going to try to slow her down. Maybe I can dissuade her from coming into Sans’ room?  
___  
-THUD THUD THUD-  
“PAPYRUS! Open up!”  
“I’M COMING UNDYNE! PLEASE DON’T BREAK THE DOOR AGAIN!”  
I rush to the door and open it.  
“HELLO UNDYNE! CAN I OFFER YOU SOMETHING TO DRINK?”  
“No. I want to check on the punk. If he’s lazing about in his room or at Grillby’s, then he’s out a job.” Undyne said as she stomped up the stairs towards Sans’ room. I followed behind her, trying to persuade her to stop or at least wait a minute. However, my attempts didn’t work, and we were at Sans’ door all to soon. Undyne barges in, then stops suddenly, causing me to bump into her back. Moving around her, I see her staring at Sans, eye wide. I look too, scared of what I might see. I had never seen Undyne react like this before.  
Sans lays in his bed, with the blanket up to his hips. He’s shaking, bones making a faint rattling noise. Magical sweat coats his bones, dripping down to further soak the bed beneath him. Tears continue to occasionally roll down his face. His pain’s gotten worse.  
I make my way over to him, sitting beside him and gently lifting him into a sitting position. I hear him gasp, but instead of reacting I reach beside the bed to pick up the sea tea I had left there earlier. It was still partially full, and I offered it to him to drink. Sans managed to drink a little, but not as much as I think he should. Gently, I lay him back down. Using the clean water and washcloth I had brought up before Undyne came, I gently wipe off his bones. Undyne continues to gape, and when I finish I gently lead her out of Sans’ room, and shut the door.  
“I TOLD YOU HE WAS SICK, UNDYNE. I WASN’T LYING.”  
“Papyrus, that’s much more than just ‘being sick.’ Tell me what’s going on. Now.”  
“O-OKAY. I DON’T KNOW MUCH, I JUST FOUND OUT ABOUT IT AND SANS HATES TO TALK ABOUT IT, BUT I’LL TELL YOU WHAT I KNOW.”  
“BACK BEFORE ALPHYS, THERE WAS ANOTHER ROYAL SCIENTIST, NAMED W.D. GASTER. SANS EXPLAINED THAT AN ACCIDENT HAPPENED DURING GASTER’S DEATH THAT CAUSED HIM TO BE ERASED FROM EXISTENCE. ANYWAY, HE WAS OUR.... WELL, I GUESS THE CLOSEST WORD IS ‘FATHER’ BUT HE DOESN’T SEEM LIKE MUCH OF ONE. HE EXPERIMENTED ON SANS AND I. IT’S WHAT CAUSED THE SCARS ON MY HANDS, AND SANS HAS CHRONIC PAIN AND LOW STATS AS A RESULT.”  
“What the FUCK? If this Gaster asshole was still alive he wouldn’t be for much longer.”  
“UNDYNE!! DON’T SAY SUCH THINGS! ANYWAY, WE HAVEN’T TOLD ANYONE ASIDE FROM YOU BECAUSE SANS DOESN’T WANT TO BE TREATED LIKE A BABYBONES. AND HONESTLY, NEITHER OF US WANT PITY.”  
“Papyrus…”  
“I’M SERIOUS, UNDYNE. WE DON’T WANT TO BE TREATED DIFFERENTLY. PLEASE DON’T DO SO YOURSELF.”  
“OK. I’m… going to leave you to care for Sans now. Just let me know the next time he needs a day off. I’ll understand.”  
“THANK YOU, UNDYNE.”


	3. Asgore

**Summary for the Chapter:**

> Sans has work to do as Asgore's Judge. But can he hide his pain from Asgore, when it's only getting worse?

**Notes for the Chapter:**

> Whoo, it's been awhile. Sorry. I had some personal issues pop up and college is taking it's toll on me. Anyway, chapter time! Enjoy!

_SANS POV_  
Asgore summoned me to act as Judge today. It’s been awhile since I’ve last done this, and I honestly don’t want to today, since I’m still recovering from a handful of bad pain days and a slightly worse than normal ache still lingers in my bones. But, this job pays well and somebody has to do it. Might as well be the person who got hired to do so. I walked into the Judgement Hall quietly and headed through it towards the Throne Room. Before acting as Judge, I needed to let Asgore know I was here and get details of what was goin’ on.  
“Sup, Fluffybuns?”  
I could see Asgore startle, so he must not have heard me walk in.  
“Hello, Sans. Can I get you a cup of tea before we begin?’  
“Nah, thanks though. Tea makes me sleepy, and I’d like to get this done.”  
“Ah. Afterwards, maybe?”  
“Ya know what? Sure. It’s been awhile since I’ve had good tea.”  
“I’m glad to hear you’ll be joining me. Now, today’s case… it isn’t the most pleasant. The defendant has been accused of stealing from a local clothes shop. These clothes had been marked as donations for lower-income families, and we haven’t been able to track any of the clothes down.”  
“Alright. I’ll do my thing and drop ya a _clothesline_ if he did it.”  
“Sans, why?”  
“What can I say, puns are pretty _pundamental_ to my existence.”  
“Sans.”  
“Right. Let’s get this over with.”  
Asgore had a few Royal Guards bring in the accused monster. During the interrogation, the monster quickly admitted to stealing the clothes. I could tell that it was an honest confession, and I quickly relayed the info to Asgore. They refused to tell me or Asgore where the clothes were, though. My job was done. I could only hope that Asgore had forgotten about his invitation for tea because my pain level had gone up during the interrogation and would probably keep doing so. Shit.  
After the guilty monster was taken away, Asgore approached to remind me about tea. I couldn’t say no after I already said I would go, so I guess I’ll live through it. Hopefully. Well, I have yet to dust from a bout of pain, so I doubt it’ll happen now.

Asgore’s tea has always been delicious. I have no clue how it’s so good since I usually don’t like tea. Asgore’s tea, however, is an obvious exception. Almost better than ketchup.It’s hard to concentrate on that right now, though. Since sitting down, my pain’s been getting fucking awful and it’s taking all of my concentration to not squirm or make noise and make Asgore worry. I hope he doesn’t realize that I’m really not listening to him…  
_POV SHIFT to Asgore_  
_Sans seems awfully distracted today… I wonder if something is going on? He keeps shifting_  
_around in his chair. And, is that a wince? What?_  
“Sans, dear friend, are you feeling alright? You’ve been awfully fidgety.”  
“Huh? Oh yeah, I’m ok. Don’t worry bout me.”  
“But I do worry, Sans. This restlessness is unlike you. You can confide in me, Sans. I won’t force you to tell me about what is troubling you, but it is obvious that something is and I want you to know that you can confide in me.”  
“I… I know, Asgore. It’s just difficult. I”ve only told Paps, and I don’t like talking about it.”  
“I understand. If you choose to confide in me, I am always available for you.”  
“Alright. I should get home now though, it’s starting to get late and Paps will worry if I am gone  
for too much longer.”  
“I can walk you out, if you want.”  
“Nah thanks, I know a shortcut.”  
Sans scoots towards the edge of his chair to make the drop down to the ground. As he slides out and touches the ground, I see his face twist into a grimace and watch as he collapses.  
“SANS!?”

**Notes for the Chapter:**

> Whooop! Cliffhanger! What will happen next? Nobody knows!  
> Well, I do. But that's for me to know and you to find out.


	4. Chapter 4

**Summary for the Chapter:**

> Asgore tries to force Sans into visiting a doctor. It doesn't go well.

**Notes for the Chapter:**

> Welp, it's been awhile. Oh well. UPDATE TIME!!

“SANS!?”  
I run to the other side of the table, almost skidding past Sans on the slick floor. Frantically, I turn Sans over and CHECK him  
*HP: 0.6/1  
*He’s in pain

_What?! He never told me his max HP was so low! I thought he meant he had around 20 HP when he told me that it was low. Damn it Sans, this is an important detail. He was starting to regain consciousness, shifting around and grimacing. I try to heal him as best as I could, my mind racing to process what had just happened. What little healing I was capable of seemed to help, as his pained grimace eased away as his eye sockets opened._  
“Sans? Sans are you alright? What happened? I want answers!”  
“S-slow down, Asgore. Gimme a sec. Ngh… Did I pass out?”  
“Yes, Sans. And I want an explanation, no shrugging it off.”  
“Alright. But can I get a place to sit? Evry’thin hurts.”  
“Of course. Can you walk?”  
“Mhm. Slowly.”  
I stood up and watched as Sans struggled to his feet. I would have offered to help, if I thought Sans would accept it. Instead, I stuck close as he climbed back into his chair.  
“Ya don’t have to hover, Asgore. Been dealin with this a long time now.”  
“Sans?”  
“Alright. Explanation. Ya don’t remember, but a long time ago we had a Royal Scientist named W. D. Gaster. He’s the one who built the Core. Ya ended up askin him to find a way to break the barrier without human Souls, and he took it a bit too far. He started to try and make artificial human Souls, and he failed. But he succeeded in making artificial monster Souls. Most of them died, but two-Papyrus and I- survived. So, he experimented on us both. A lot. It’s what fucked my stats over, and it’s given me chronic pain as a result. Some days are better than others, but the last 3 days were really bad and I didn’t give myself enough time to recover. But I’ll be OK.”  
“Sans… why didn’t you tell me about this earlier? I could have helped…”  
“I knew ya would blame yourself. And I didn’t want that. This is Gaster’s fault alone.”  
“Sans, why don’t I remember him?”  
“He fell into the Core. It erased him from existence. Only I remember him.”  
“Oh. And have you seen a doctor for your troubles, Sans?”  
“No. I don’t like doctors. For obvious reasons.”  
“Sans, you need to go. They could help-”  
“No, Asgore. I am not going.”  
“Sans. As your friend and King, I insist that you go. I will call my private doctor immediately.”  
“No-!”  
Sans dropped out of his chair and started running, but in a few quick strides I caught up with the small skeleton and gathered him into my arms, Sans struggling to free himself.  
“No-Please lemme go I’m sorry I don’t wanna-”  
“Sans. This is for your own good.”  
I held Sans close as I dialed my doctor’s number. The call was answered quickly, and I described Sans’s predicament. She agreed to come immediately, and I hung up the phone. I adjusted Sans in my arms. He had gone mostly quiet, just muttering as he shook.  
“I’m so sorry, Sans. But I’m worried for you.”

The doctor arrived in short order, and I answered the door with Sans still in my arms.  
“Oh my Stars! This poor monster is in a state, what happened?”  
“He passed out during tea. When he woke up he explained that he had been experimented on in the past, and that it negatively impacted his statistics and has caused chronic pain. I was worried, so I insisted he see a doctor and called you in.”  
“Wait a minute. With respect, but you made a monster with severe medical-related trauma see a doctor against his will? Your Highness, that was not only dense of you, but it was harmful.”  
“What? But I-”  
“I know you want to help your friend, but there is nothing I can do for him in this state except calm him down. I can talk to him to set up an appointment for him at a later date, if he’s willing.”  
“Okay.”  
“Now put him down, so we can talk him out of his panic. Then we’re sending him home.  
It took us over an hour to bring Sans back to awareness, and even then, he was shaky.  
“I-i need to go home. Paps is prob worried ‘bout me.”  
“Alright, Sans. But I will walk you home, it’s the least I could do.”  
“M’kay.”

Trudging across the Underground took much longer than usual due to Sans’s slow, exhausted pace, but eventually they reached the skeleton’s home.  
“SANS! I WAS SO WORRIED! ARE YOU OK, WHAT TOOK SO LONG?”  
Papyrus had flung open the door and was frantically, yet gently, checking his brother over.  
“M’fine now, just tired. Need sleep.”  
“Alright, Brother. Go To Bed. I Will Talk To Asgore Really Quick.”  
“Mkay”  
“Care To Explain What Happened?”  
“I-I found out about what happened to you and Sans. And I tried to get Sans to go to a doctor…”  
“WHAT?!? WHY? SANS HAS NEVER WANTED TO SEE A DOCTOR, HE CAN’T STAND THEM! AND FOR GOOD REASON!!”  
“I know, and I’m sorry. I should not have insisted that Sans see a doctor. I apologize.”  
“HMPH. I’M NOT THE ONE YOU SHOULD BE APOLOGIZING TO.”  
“I know. I will come back tomorrow to apologize to Sans properly.”  
“YOU BETTER!”


	5. Chapter 5

**Summary for the Chapter:**

> Asgore apologizes, and a discussion follows.

Asgore knocked gently on the door to Sans and Papyrus’s home, a basket of fruit held in his paws.  
Sans opened the door slowly, smiling gently when he saw who was at the door.   
“Sup Asgore? What brings you here?”  
“I-I wanted to apologize. I shouldn’t have made you go to the doctor like I did.”  
“Apology accepted, Fluffybuns. Why don’t you come in, Paps is cooking soup.”  
“Not spaghetti?”  
“He insisted that soup would be easier to stomach. Which is weird, considering I don’t have one.”  
“SANS, I HEARD THAT!”  
“Hehe, classic Paps. Go ahead and sit.”  
“I brought you fruit, by the way. Thought it’d be nice.” Said Asgore, setting the basket down on the coffee table.  
“Thanks.”  
“Sans… I’m really sorry about yesterday. I crossed boundaries I shouldn’t have.”  
“Yep. It’s OK though.”  
“It really is not. And I know better now. But Sans, I really would like to discuss the possibility of you seeing a doctor, on your own time and terms, of course.”  
Sans grimaced a bit at the thought, curling into the couch cushions.  
“I’ll… Think about it. But no promises, Asgore.”  
“That’s all I ask, Sans. They could help, if you gave them a chance.”  
“... Maybe.”  
“I’ll take my leave, now. Thank you for listening.”  
“See ya later.”  
Sans walked Asgore out and closed the door behind him, heaving a deep breath after he heard the latch click into place. He then made his way into the kitchen, where Papyrus was finishing up dinner.  
“ASGORE ISN’T STAYING FOR DINNER?”  
“No Paps, he’s probably busy.”  
“SANS? WILL YOU ACTUALLY CONSIDER MAKING A DOCTOR’S APPOINTMENT?”  
“I dunno, Paps.”  
“PLEASE? I HATE SEEING YOU IN SO MUCH PAIN. AND IF THERE IS A WAY YOU COULD FEEL BETTER, YOU SHOULD TAKE IT.”  
“I’ll think on it, Paps.”  
“THANK YOU, SANS.”


End file.
